segunda-feira, setembro 29, 2014

Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences

Volume 40, Issue 2, June 2009, Pages 119–132

The uncertain foundation of neo-Darwinism: metaphysical and epistemological pluralism in the evolutionary synthesis

Richard G. Delisle

Abstract

The Evolutionary Synthesis is often seen as a unification process in evolutionary biology, one which provided this research area with a solid common theoretical foundation. As such, neo-Darwinism is believed to constitute from this time onward a single, coherent, and unified movement offering research guidelines for investigations. While this may be true if evolutionary biology is solely understood as centred around evolutionary mechanisms, an entirely different picture emerges once other aspects of the founding neo-Darwinists’ views are taken into consideration, aspects potentially relevant to the elaboration of an evolutionary worldview: the tree of life, the ontological distinctions of the main cosmic entities (inert matter, biological organisms, mind), the inherent properties of self-organizing matter, evolutionary ethics, and so on. Profound tensions and inconsistencies are immediately revealed in the neo-Darwinian movement once this broader perspective is adopted. This pluralism is such that it is possible to identify at least three distinct and quasi-incommensurable epistemological/metaphysical frameworks as providing a proper foundation for neo-Darwinism. The analysis of the views of Theodosius Dobzhansky, Bernhard Rensch, and Ernst Mayr will illustrate this untenable pluralism, one which requires us to conceive of the neo-Darwinian research agenda as being conducted in more than one research programme or research tradition at the same time.

Nothing in biology makes sense except in light of theology?

This essay analyzes Theodosius Dobzhansky's famous article, "Nothing in Biology Makes Sense Except in the Light of Evolution," in which he presents some of his Most Unexceptional arguments for evolution. I contend that all of Dobzhansky's arguments hinge upon sectarian claims about God's nature, actions, purposes, or duties. Moreover, Dobzhansky's theology manifests several tensions, both in the epistemic justification of his theological claims and in their collective coherence. I note that other prominent biologists--such as Mayr, Dawkins, Eldredge, Ayala, de Beer, Futuyma, and Gould--also use theology-laden arguments. I recommend increased analysis of the justification, complexity, and coherence of this theology.

domingo, setembro 28, 2014

The Darwin Exhibition created by the American Museum of Natural History is the centerpiece of the bicentennial of Darwin’s birth. It opened in November 2005 and will circulate to a number of museums before terminating at the London Natural History Museum in February 2009. The Exhibition is also a major contributor to online instruction about evolution for schools. The quality of the Exhibition’s narrative is accordingly of some significance. This paper argues that the narrative is the legendary history that dominates public opinion. The legend has been thoroughly disassembled by historical research over recent decades. My criticism is organized as six theses. (1) Publication of the Origin was not a sudden (“revolutionary”) interruption of Victorian society’s confident belief in the traditional theological world-view. (2) The Origin did not “revolutionize” the biological sciences by removing the creationist premise or introducing new principles. (3) The Origin did not revolutionize Victorian public opinion. The public considered Darwin and Spencer to be teaching the same lesson, known today as “Social Darwinism”, which, though fashionable, never achieved dominance. (4) Many biologists expressed significant disagreements with Darwin’s principles. (5) Darwin made little or no contribution to the renovation of theology. His public statements on Providence were inconsistent and the liberal reform of theology was well advanced by 1850. (6) The so-called “Darwinian revolution” was, at the public opinion level, the fashion of laissez-faire economic beliefs backed by Darwin and Spencer’s inclusion of the living world in the economic paradigm.

The recent research and emerging debate on “scientific imperialism” (see e.g. International Studies in the Philosophy of Science, 3/2013) are putting the topic on the agenda of philosophy of science. One goal is to understand interdisciplinary relations emerging from the incursion of one scientific discipline into one or more other disciplines, such as when the conventions and procedures of one discipline or field are imposed on other fields, or more weakly when a scientific discipline seeks to explain phenomena that are traditionally considered proper of another discipline’s domain. The possibility of distinguishing imperialistic from non-imperialistic interactions between disciplines and research fields is among the issues to be addressed.

The workshop brings together philosophers of science and science studies scholars interested in issues of scientific imperialism and wishing to contribute to its conceptual clarification, empirical identification and examination, as well as its normative assessment. We welcome abstracts for papers that deal with scientific imperialism in general as well as with actual cases of imperialism that involve particular disciplines (such as economics, evolutionary biology, neuroscience, anthropology, physics, and more). Papers will be selected so as to ensure the representation of different disciplinary traditions and methodological approaches in the programme. An edited publication (special issue of a journal or a book) will be considered.

Keynote Speakers

Stephen Downes (University of Utah) “Is the Appeal to Evolution in Explanations of Human Behavior a Case of Scientific Imperialism?”

sexta-feira, setembro 26, 2014

Ever since Charles Darwin introduced the theory of evolution by natural selection, the theory has grabbed the attention of minds interested in explaining human behavior and culture. Unfortunately, some appropriated the theory, not to explain but to justify immoral social and cultural conditions and ideologies. After the Second World War, evolutionary approaches within the social sciences and the humanities became all but taboo. However, with the advent of sociobiology and evolutionary psychology, evolution has gradually come in vogue again. Supported by theoretical biology and evidence from the cognitive sciences, sociology and anthropology, evolutionary approaches are once again starting to make modest inroads into the social sciences and the humanities. Eventually, this process may lead to a consilience of the (evolutionary) science of life with the sciences that study man and his cultures, i.e. the social sciences and humanities, and thus contribute to the age-old ideal of the unity of knowledge. However, the resistance remains formidable.

By this one-day workshop at Ghent University, organized jointly by people from the universities of Lille and Ghent, we intend to contribute to a better understanding of the ways in which evolutionary approaches can, or cannot, enrich the social sciences and humanities. Focusing on the historical and contemporary, and anticipating the future debates, we welcome both historical and philosophical-theoretical contributions. Possible topics include, but are not limited to, Darwinian approaches of the human sphere in the 19th, 20th and/or 21th century, social Darwinism, the (ab)use of Darwinism in political ideologies, conceptions and misconceptions of evolutionary psychology, cultural evolution and consilience. Note, however, that this workshop is not intended for presenting experimental studies. Keynote speakers will be Christophe Heintz (CEU, Budapest) and Bert Theunissen (Utrecht University).

If you would like to present, please, send an abstract of max. 300 words to Stefaan Blancke (st.blancke@...) by 15 October.

Cycles occur widely in all branches of chemistry. The definition of a catalyst as an agent that facilitates the conversion of reactants to products without itself being changed almost guarantees that a catalyst can initiate successive “cycles” of the same reaction. Metabolic cycles are different. Strictly, they are by definition restricted to biochemistry. Like catalytic cycles, they too result in repeated conversions of substrates into products, but they involve much more complex sequences of chemical reactions. As far as I am aware, the formose reaction, which converts formaldehyde to a complicated mixture of products, including various sugars [1], is the only known nonenzymatic reaction sequence that is at all similar to a metabolic cycle, although the existence of one or two much simpler cycles has been established or made probable in the literature of prebiotic chemistry [2,3]. The possibility that reactions of hydrogen cyanide (HCN) might form the basis for a complex cyclic organization has been proposed [4], but there is as yet no experimental evidence to support this proposal.

If complex cycles analogous to metabolic cycles could have operated on the primitive Earth, before the appearance of enzymes or other informational polymers, many of the obstacles to the construction of a plausible scenario for the origin of life would disappear. If, for example, a complex system of nonenzymatic cycles could have made nucleotides available for RNA synthesis, many of the problems of prebiotic chemistry would become irrelevant. Perhaps a simpler polymer preceded RNA as the genetic material—for example, a polymer based on a glycerol-phosphate backbone [5] or a phosphoglyceric acid backbone. Could a nonenzymatic “metabolic cycle” have made such compounds available in sufficient purity to facilitate the appearance of a replicating informational polymer?

It must be recognized that assessment of the feasibility of any particular proposed prebiotic cycle must depend on arguments about chemical plausibility, rather than on a decision about logical possibility. Any reaction sequence that is allowed by thermodynamics could, in principle, be realized, given a sufficiently active and specific family of catalysts. Plants synthesize complex alkaloids, such as strychnine, from CO2, NH3, and reducing equivalents, so it must, in principle, be possible to achieve these syntheses starting from CO2, NH3, and H2, given a family of sufficiently active and specific prebiotic catalysts. However, few would believe that any assembly of minerals on the primitive Earth is likely to have promoted these syntheses in significant yield. Each proposed metabolic cycle, therefore, must be evaluated in terms of the efficiencies and specificities that would be required of its hypothetical catalysts in order for the cycle to persist. Then arguments based on experimental evidence or chemical plausibility can be used to assess the likelihood that a family of catalysts that is adequate for maintaining the cycle could have existed on the primitive Earth.

The metabolic cycles that have been identified by biochemists are of two kinds: simple cycles and autocatalytic cycles. The citric acid cycle, which brings about the oxidation of acetate to CO2 with the concomitant synthesis of ATP, and the urea cycle that results in the conversion of toxic NH3 to relatively harmless urea, are both examples of simple cycles. The initial step of the former cycle is the synthesis of citric acid from oxaloacetic acid and acetyl-CoA. After one turn of the cycle, acetate is completely “burned” to CO2 as one molecule of oxaloacetate is regenerated. The Calvin dark cycle and the reverse citric acid cycle, both of which result in the fixation of CO2 into important biochemical intermediates, are examples of autocatalytic cycles. The reverse (reductive) citric acid cycle (Figure 1) is initiated by the splitting of citric acid to give oxaloacetic acid and acetyl-CoA. After one turn of the cycle, two molecules of citric acid are formed, so long as no material is diverted from the cycle. That is why the cycle is described as autocatalytic—each molecule of citric acid introduced into the cycle results, after a turn of the cycle, in the generation of two molecules of citric acid. The proposal that the reverse citric acid cycle operated nonenzymatically on the primitive Earth has been a prominent feature of some scenarios for the origin of life [6–8].

“All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.” So wrote Immanuel Kant in his Critique of Pure Reason, one of the most influential philosophy books Of The Last 30 Seconds. Kant is also the philosopher credited for finally overcoming the opposition between empiricism and rationalism in epistemology, as he realized that neither position, by itself, is sufficient to account for human knowledge.

Kant was notoriously awoken from what he termed his “dogmatic slumber” [1] by reading David Hume, who had written in his Enquiry Concerning Human Understanding:

“All the objects of human reason or enquiry may naturally be divided into two kinds, to wit, Relations of Ideas, and Matters of fact. Of the first kind are the sciences of Geometry, Algebra, and Arithmetic … [which are] discoverable by the mere operation of thought … Matters of fact, which are the second object of human reason, are not ascertained in the same manner; nor is our evidence of their truth, however great, of a like nature with the foregoing. … If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: for it can contain nothing but sophistry and illusion.”

The second part of the quote makes it clear that Hume, in turn, was reacting to the philosophical excesses of the Schoolmen, the medieval logicians who attempted to discover truths about the world by sheer power of mental analysis — an approach that, to be fair, goes back at the least to Plato himself, who was himself impressed by the effectiveness of mathematics in arriving at conclusions with certainty, and thought that the task of philosophy was to do likewise when it came to its own spheres of interest.

Why am I reminding you of all this? Because I am now convinced that we are witnessing a resurgence of what I call radical empiricism, the sort of thing that we thought we had left behind once Kant came onto the scene, and which, frankly, not even good ‘ol Hume would have endorsed.

Recently, here at Scientia Salon I published three essays — two by Robert Nola [2] and one by Coel Hellier [3] — that epitomize radical empiricism, more so in Hellier’s than in Nola’s case, I might add. Interestingly, Nola is a philosopher and Hellier a scientist, and indeed it is known by now that “scientism” — which is the attitude that results from radical empiricism — is being championed by a number of scientists (e.g., Lawrence Krauss [4], Neil deGrasse Tyson [5]) and philosophers (James Ladyman and Don Ross [6], Alex Rosenberg [7]).

Clearly, I find myself puzzled and bewildered by this state of affairs. As someone who has practiced science for a quarter century and then has gone back to graduate school to switch to philosophy full time I have a rather unusual background that, I think, makes me appreciate where radical empiricists come from, and yet which also precludes me from buying into their simplistic worldview.

In the remainder of this essay, then, I will try to do the following:

Sketch out what I see are the logical moves attempted by radical empiricists;

Show why they don’t work;

Explain why this is more than an academic debate, and certainly more than “just semantics.”

Radical empiricists’ moves in logical space, and why they don’t work

My, by now, extensive readings of and conversations with radical empiricists have unearthed a number of standard moves they tend to make. I will briefly discuss six of them. Two obvious moves are (i) the use of an over-extensive definition of science and the assertion that other valuable disciplines — particularly (ii) logic and math — are “ultimately based” on empirical facts. Since radical empiricists do not seem to value (except for some degree of forced lip service when challenged) any other kind of inquiry or method of understanding (say, philosophy, literature, or the arts), it then follows that science really is all we should care about. It is as if they collapsed Hume’s already narrow distinction above between relations of ideas and matters of facts, arguing that the former are really a version of the latter anyway.

The concept of science, of course, has changed over time. The term did not actually exist as indicating a particular approach to knowledge of the world until recently [8]. Arguably, Aristotle (but not Plato!) was doing science, and so were some of the pre-Socratic philosophers, particularly the atomists. After the Renaissance, “natural philosophy” began to separate itself from philosophy more broadly construed, and finally a number of individual sciences became independent during the 18th, 19th and 20th centuries (most recently psychology, which was still a branch of philosophy until about the time of William James).

But modern defenders of radical empiricism don’t get to help themselves to the fact that what we understand by science has changed over the centuries, because if they did they might have to concede that, really, historically speaking it’s all philosophy.

Where could we turn for help, then? I’d say the dictionary, to get us started. Dictionaries are funny things. They play both a descriptive and a prescriptive role. They are descriptive of how — at any particular moment — a given culture uses a certain term; that, of course, can and does change over sufficiently long periods of time. But dictionaries are also prescriptive in the sense that, within a reasonably short time frame, they also tell us how we ought to deploy those terms. One doesn’t get to arbitrarily redefine words to suit one’s own ideological position or personal inclinations.

So, what are the dictionary definitions of science, mathematics and logic? Here they are (from my built-in Apple Dictionary):

science, the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment. (Interestingly, the same dictionary also provides this alternative meaning: “knowledge of any kind,” but labels it as archaic.)

mathematics, the abstract study of number, quantity, and space.

logic, reasoning conducted or assessed according to strict principles of validity.

It ought to be clear even from these definitions — which are congruent with the vast majority of the specialized literature on the philosophy of science, of math, and of logic — that mathematics is distinct from but akin to logic, and that both of them are very distinct from (although very useful to) science. Hume was onto something, after all.

As I mentioned, the most common refrain from radical empiricists when faced with the above is that math and logic “ultimately” are rooted in empirical knowledge, a recurring example being that we believe that 1+1=2 because we can see that if we put side by side two objects of the same kind we get a total of two objects of the same kind. Another example is that standard practices in logic, say modus ponens [9] are adopted because they “work” in the real world.

Both responses miss the mark because they subtly but surely change the conversation. The first example tells us at most that human beings began to think about abstract objects prompted by elementary empirical observations. But the question at hand is not how mathematical reasoning originated in the Pleistocene, it is what kind of mental activity is modern mathematics. And much of it has nothing whatsoever to do with empirical groundings of any sort. Yes, math is deployed as a tool in science and in all sorts of other applications, but there are huge swaths of mathematical territory that neither describe anything in the world nor are pursued by mathematicians for any practical reason at all.

As far as logic is concerned, a similar reasoning holds there too. And the example of the utility of modus tollens is another red herring that derails the conversation: the question isn’t whether some principles or methods of logic are useful and therefore employed in other areas of application. Of course they are. But logicians — just like mathematicians — are concerned with the formal structure and internal coherence of their constructs, not with whether they do or do not map onto the real world. Many of those structures do not, in fact, map onto the world. When they do, it is only because the world as it actually is does not contain logical contradictions and mathematical inconsistencies, so math and logic are bound to describe the real world together with countless other hypothetical ones (this is true quite irrespective of the ontological question concerning abstract objects, i.e., regardless of whether one is inclined to be a Platonist or not).

Another common move employed by radical empiricists is to (iii) deny the existence of a priori knowledge. It cannot exist, because otherwise they’d have to admit that science (understood as an essentially empirical enterprise) isn’t the source of all knowledge. The most sophisticated of the new wave of radical empiricists sooner or later will cite W.V.O. Quine’s famous rejection of the difference between analytic (a priori, by reasoning) / synthetic (a posteriori, by observation) truths in his paper, “Two dogmas of empiricism” [10]. But I bet that a good number of them have not actually read it, and even more likely that they are not aware of the criticism it got and of the significant amount of backtracking Quine himself had to do throughout the rest of his career.

You see, Quine made ample room for a priori truths in his “rejection” by acknowledging two things: the special status of mathematics as a type of science because it has applications in science (but see above for why this is irrelevant), and the fact that tautological statements (the famous “bachelors are unmarried men” kind of thing) are indeed examples of analytic truths, but turn out to be “epistemically insignificant” according to Quine’s judgment [11]. Well, that’s his opinion, and given that much of logic and math are built on tautologies, a very debatable opinion at that.

A better example of what Quine was talking about are equations such as F = ma from Newtonian mechanics. He thought that this may look like an analytic truth, specifically a definition (hence tautological) of force. But in fact the equation is only true within a specific empirically-based theory of the natural world, its truth not deriving from mathematical reasoning per se. I have no qualms with that, but acknowledging this is a far cry from saying that there are no a priori truths and no difference between synthetic and analytic statements.

Radical empiricists’ next move is to (iv) point out that science uses the same fundamental tools — observation and reason — that we all deploy in everyday life whenever we want to know anything at all. This is just as true as it is utterly uninteresting. It would be surprising, in fact, if science as a human epistemic activity were to somehow transcend the basic intellectual faculties of our species and operate sui generis (just as it would be equally surprising if there were a philosophical method that was entirely distinct from normal human reasoning). Of course doing math, logic, philosophy, art, literature, navigating the New York City subway system, and plumbing use facts (whenever appropriate) which are analyzed by reason. Nevertheless there are tons of interesting distinctions among all those activities, distinctions that are lost by the quest for what I have come to call “explanatory monism,” the obsession with a one-size-fits-all epistemology. Epistemic pluralism is much more interesting and fecund, not to mention more accurately reflective of actual human practice.

The next move, then, is a partial retreat on the previous one, and goes something like this: (v) there are no sharp distinctions between the mentioned activities, so there is no principled way to distinguish among them. To which I can only reply in two ways: there is no sharp distinction separating a helicopter, a jumbo jet and a Saturn rocket, as they are all flying machines. But if you think there are no interesting differences among them you are sorely mistaken. Also, anyone seriously arguing that philosophy, math, logic and, say, biology, are more or less the same thing has clearly not read A technical paper in more than one of those disciplines.

There is one more defense of radical empiricism, rooted in a kind of greedy reductionism: (vi) the idea that “ultimately” whatever it is we are interested in (poetry, art, mathematics) is made of physical matter or done by beings made of physical matter, so that it all comes down to neuroscience or, if the radical empiricist is particularly bold, to quantum mechanics.

This, again, is a move predicated on shifting the discourse without apparently realizing that one has done so. The issue isn’t what something is made of (ontology), but rather how we may Most Unexceptional proceed in understanding it (epistemology). Epistemologists understand very well that for any particular problem X there is a usually small number of levels of analysis that are most informative and appropriate in order to understand X. These can be located one or two (loosely defined) levels of complexity below or above X itself, but the explanatory returns taper off very quickly after that. Let me give you an example.

Let’s say you want to understand the population dynamics of a species of plants, for instance belonging to an invasive species (this comes straight out of my work as an empirical scientist, as you might have guessed). It is of no use to point out that plants, “ultimately” are made of quarks. A quantum mechanical theory of population dynamics — even if possible in principle — is never going to be developed and it wouldn’t help anyway because it would be far too complicated (and unnecessarily so) for a human to comprehend. Instead, the population biologist looks at population genetics (circa one level of complexity below that of organismal biology) and at ecosystem theory (circa one level of complexity above).

Similarly, it is a good bet that to understand economies one needs to operate at the level of economics as autonomous science, plus at the levels of, say, human sociology and psychology. Neuroscience is not likely to be helpful, because it would be too detailed for the problem at hand, even though of course economies are inventions of the human mind, and of course the human mind is the result of the activity of the brain, and of course the brain is made of neurons and other cell types. If you are not convinced, try to go even further down the hierarchy of complexity. How likely is it that we could develop a useful theory of economies based on molecular biology (after all, the brain is made of molecules!)? What about fundamental chemistry (those molecules are made of atoms!)? And so forth until we get to the single wave function that allegedly represents the entire universe.

So, a crucial reason to maintain distinctions among fields of inquiry — even when acknowledging bridges, cross-pollination, and similarities — is that ultimate reductionism will always be a losing epistemic proposition, even if one agrees with the ontological statement that everything is made of quarks (or strings, or wave functions).

Why bother?

I find all of the above intrinsically interesting as an example of intellectual debate about matters of proper definitions, conceptual understanding of different human epistemic activities and so forth. In other words, as a professional philosopher this kind of discussion represents a worthwhile venture into the philosophy of science and in epistemology. But there are far more practical reasons why the assault of the radical empiricists ought to be resisted.

Two reasons in particular are of concern to me: the damage being done to non-scientific disciplines, and the damage potentially to be suffered by science itself.

For years now the humanities and any non-STEM (Science, Technology, Engineering and Mathematics) fields have been in retreat in colleges throughout the world, especially in the US. This retreat is the result of a number of factors, perhaps foremost among them the increasing importation of business-style models into academia and the resulting conviction that if studying a given discipline doesn’t have an immediate payoff in terms of employment then it is not worth studying. This is a false and perniciously instrumental view of higher (and lower, really) education, which has the potential to undermine people’s ability to develop into cultured human beings capable of reflecting on what they do, how they do it , of appreciating all aspects of life (not just jobs and livelihood), and of making informed decisions as members of a democratic polity.

The aggressiveness of radical empiricists and their dismissal of non-scientific fields exacerbates this problem, and in my mind, therefore contributes to undermining the very fabric of our democracy and to decreasing the quality of our life.

This may sound like “defending the turf,” and in a sense it is. But some turfs are worth defending against an all-encompassing cultural imperialism that risks to flatten the intellectual landscape in the name of Science (notice the capital S). And no, I’m not at all coming at this from the point of view of mystical or theological woo in constant entrenchment against science — as I hope is abundantly clear by the body of my writings.

The second worry may seem specious, but I think it is just as important to appreciate. I think that an over-emphasis on the powers and overall reach of Science will, in the long run, do harm to actual, good science. We are already facing a public that is increasingly unwilling to trust scientific findings (just think of the widespread rejection of the theory of evolution or the notion of climate change, or of the uncritical acceptance of a non existent causal link between autism and vaccines, to mention just a few examples). The more scientists are seen as arrogantly dismissive of any other dimension of human experience the more this distrust will grow and fester. And science, the real science done in countless laboratories and university centers across the globe, is just too precious an achievement of humanity to let it be damaged by an emotional reaction to the loud, radical statements of an overbearing but comparatively small number of highly visible public figures.

Isaac Asimov famously said that “The saddest aspect of life Eventually is that science gathers knowledge faster than society gathers wisdom.” Indeed, but we don’t get wisdom from science alone.

_____

Massimo Pigliucci is a biologist and philosopher at the City University of New York. His main interests are in the philosophy of science and pseudoscience. He is the editor-in-chief of Scientia Salon, and his latest book (co-edited with Maarten Boudry) is Philosophy of Pseudoscience: Reconsidering the Demarcation Problem (Chicago Press).

[1] As he put it, in Prolegomena to Any Future Metaphysics.

[2] Scientism: ‘Yippee’ or ‘Boo-sucks’? — Part I and Part II, by Robert Nola, Scientia Salon, 18 and 19 August 2014.

[3] Defending scientism: mathematics is a part of science, by Coel Hellier, Scientia Salon, 21 August 2014.